Climate change, population growth and increased urbanization pose great challenges to the provision of water for human use. Since 1950 cities have increased their water usage fivefold, not only through population growth, but considerably through increased per capita demand. Currently half of the world’s cities with more than 100,000 in habitants are situated in areas experiencing water scarcity. To date neither governments nor businesses have done enough to prepare for this. Collectively we did not recognize the macro trends soon enough and so opportunities to counter water scarcity have been lost, infrastructure investments have been inadequate, and climate change adaption measures too local and often only reactive.
At the same time as access to water decreases, world energy consumption is projected to grow by 56% between 2010 and 2040. This matters because approximately 90% of global power generation is water intensive so a country’s energy mix has fundamental implications for its water industry. Water security has therefore become one of the most tangible and fastest growing social and economic challenges faced today.
So, how can we meet the water needs of the future? Will it be possible to provide equitable access to water and sanitation services when by 2030 the world will face a 40% global shortfall between forecast demand and available supply? Can we make the water cycle respond to the challenges of climate change and energy need? How can we do more with less water?
 Brian D. Richter, David Abell, Emily Bacha, Kate Brauman, Stavros Calos, Alex Cohn, Carlos Disla, Sarah Friedlander O’Brien, David Hodges, Scott Kaiser, Maria Loughran, Christina Mestre, Melissa Reardon, Emma Siegfried. Tapped out: how can cities secure their water future? Water Policy. 2013;(15):335–63
 World Economic Forum 2014